What are Sampled Values?
Sampled Values is mechanism to publish sampled analog measurements from measurement devices like current transformers (CT) and voltage transformers (VT). Sampled Values messages are “published” by a device via Ethernet multicast such that they can be “subscribed” by any number of other devices. Unlike GOOSE, Sampled Values are not event driven but instead sample driven. The samples are measured at a specific sampling rate and use a specific dataset. Sampled Values publishers are typically referred to as merging units and subscribers would be some type of IED.
Exampled: The 9-2 LE profile for Sampled Values has a sampling rate of 80 or 256 samples/cycle (the cycle could be based on a system frequency of 50 Hz or 60 Hz). The dataset for 9-2 LE includes measurements for 3 phase and neutral for both CTs and VTs.